IBC-Ox32 Streamlining preoperative risk assessment: counterintuitive results in the Bariatric patient

Background

Bariatric surgical operations continue to be performed in high numbers nationally, thus it is important to identify factors associated with post-surgical complications. This study aims to identify preoperative risk factors associated with bariatric surgery mortality.

Methods

A retrospective analysis was conducted on the Metabolic and Bariatric Surgery Accreditation and Quality Improvement Program database to determine the strength of association between pre-operative exposures and 30-day mortality following bariatric surgery. A total of 701,265 primary bariatric operations were registered between the years of 2015 and 2017, consisting of sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB), adjustable gastric band (AGB), and duodenal switch (DS)

Results

From the 701,265 surgeries registered in the database, 636,286 had complete data points for the variables of interest and therefore were included in this analysis. The mean age of the cohort was 45.01 (SD= 11.96) years, mean BMI was 45.54 kg/m2 (SD=7.72), and 80.07% were female. Overall 30-day mortality was 0.10% (n=629). The association between the following preoperative variables and mortality within 30 days of bariatric surgery was not statistically significant: hyperlipidemia, history of pulmonary embolism, oxygen dependence, obstructive sleep apnea and history of venous stasis. Smoking status (AOR=1.38), insulin dependent diabetes (AOR=1.37) and the use of more than 3 hypertensive medications (AOR=1.30) were weakly associated with postoperative mortality (p<0.05; CI=95%). History of chronic obstructive pulmonary disease (COPD; AOR=2.00), partial functional dependency (AOR=2.09), renal insufficiency (AOR=1.63), dialysis (AOR=3.15), history of deep venous thrombosis (AOR=1.78), history of myocardial infarction (AOR=1.65) and history of cardiac surgery (AOR=1.87) were strongly associated with mortality (P<0.05; c.i. = 95%)

Conclusion

Bariatric surgery continues to be safe. Many factors that have traditionally been thought to contribute to mortality, such as diabetes, hypertension, smoking, and oxygen dependence may have little impact. Other variables such as previous heart surgery, functional dependency status and COPD may play a bigger role in adverse outcomes. While these associations do not determine causality, understanding the strength of them can guide physicians on preoperative risk assessment and care.

Body Weight and Prandial Variation of Plasma Metabolites in Subjects Undergoing Gastric Band-Induced Weight Loss

BACKGROUND

Bariatric procedures are safe and effective treatments for obesity, inducing rapid and sustained loss of excess body weight. Laparoscopic adjustable gastric banding (LAGB) is unique among bariatric interventions in that it is a reversible procedure in which normal gastrointestinal anatomy is maintained. Knowledge regarding how LAGB effects change at the metabolite level is limited.

OBJECTIVES

To delineate the impact of LAGB on fasting and postprandial metabolite responses using targeted metabolomics.

SETTING

Individuals undergoing LAGB at NYU Langone Medical Center were recruited for a prospective cohort study.

METHODS

We prospectively analyzed serum samples from 18 subjects at baseline and 2 months after LAGB under fasting conditions and after a 1-hour mixed meal challenge. Plasma samples were analyzed on a reverse-phase liquid chromatography time-of-flight mass spectrometry metabolomics platform. The main outcome measure was their serum metabolite profile.

RESULTS

We quantitatively detected over 4,000 metabolites and lipids. Metabolite levels were altered in response to surgical and prandial stimuli, and metabolites within the same biochemical class tended to behave similarly in response to either stimulus. Plasma levels of lipid species and ketone bodies were statistically decreased after surgery whereas amino acid levels were affected more by prandial status than surgical condition.

CONCLUSIONS

Changes in lipid species and ketone bodies postoperatively suggest improvements in the rate and efficiency of fatty acid oxidation and glucose handling after LAGB. Further investigation is necessary to understand how these findings relate to surgical response, including long term weight maintenance, and obesity-related comorbidities such as dysglycemia and cardiovascular disease.

Prior bariatric surgery in COVID-19-positive patients may be protective

Background

Patients infected with novel COVID-19 virus have a spectrum of illnesses ranging from asymptomatic to death. Data have shown that age, sex, and obesity are strongly correlated with poor outcomes in COVID-19–positive patients. Bariatric surgery is the only treatment that provides significant, sustained weight loss in the severely obese.

Objectives

Examine if prior bariatric surgery correlates with increased risk of hospitalization and outcome severity after COVID-19 infection.

Setting

University hospital

Methods

A cross-sectional retrospective analysis of a COVID-19 database from a single, New York City–based, academic institution was conducted. A cohort of COVID-19–positive patients with a history of bariatric surgery (n = 124) were matched in a 1:4 ratio to a control cohort of COVID-19–positive patients who were eligible for bariatric surgery (BMI ≥40 kg/m² or BMI >35 kg/m² with a co-morbidity at the time of COVID-19 diagnosis) (n = 496). A comparison of outcomes, including mechanical ventilation requirements and deceased at discharge, was done between cohorts using χ² test or Fisher’s exact test. Additionally, overall length of stay and duration of time in intensive care unit (ICU) were compared using Wilcoxon rank sum test. Conditional logistic regression analyses were done to determine both unadjusted (UOR) and adjusted odds ratios (AOR).

Results

A total of 620 COVID-19–positive patients were included in this analysis. The categorization of bariatric surgeries included 36% Roux-en-Y gastric bypass (RYGB, n = 45), 36% laparoscopic adjustable gastric banding (LAGB, n = 44), and 28% laparoscopic sleeve gastrectomy (LSG, n = 35). The body mass index (BMI) for the bariatric group was 36.1 kg/m² (SD = 8.3), which was significantly lower than the control group, 41.4 kg/m² (SD = 6.5, P < .0001). There was also less burden of diabetes in the bariatric group (32%) compared with the control group (48%) (P = .0019). Patients with a history of bariatric surgery were less likely to be admitted through the emergency room (UOR = .39, P = .0001), less likely to require a ventilator during the admission (UOR=.42, P = .028), had a shorter length of stay in both the ICU (P = .033) and overall (UOR = .44, P = .0002), and were less likely to be deceased at discharge compared with the control group (OR = .42, P = .028).

Conclusion

A history of bariatric surgery significantly decreases the risk of emergency room admission, mechanical ventilation, prolonged ICU stay, and death in patients with COVID-19. Even when adjusted for BMI and the co-morbidities associated with obesity, patients with a history of bariatric surgery still have a significant decrease in the risk of emergency room admission.

c-MAF-dependent perivascular macrophages regulate diet-induced metabolic syndrome

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Gastric band conversion to Roux-en-Y gastric bypass shows greater weight loss than conversion to sleeve gastrectomy: 5-year outcomes

BACKGROUND

Roux-en-Y gastric bypass (RYGB) and laparoscopic sleeve gastrectomy (LSG) are often used as revisional surgeries for a failed laparoscopic adjustable gastric band (LAGB). There is debate over which procedure provides better long-term weight loss.

OBJECTIVE

To compare the weight loss results of these 2 surgeries.

SETTING

University hospital, United States.

METHODS

A retrospective review was conducted of all LAGB to RYGB and LAGB to LSG surgeries performed at a single institution. Primary outcomes were change in body mass index (BMI), percent excess BMI lost, and percent weight loss. Secondary outcomes included 30-day complications and reoperations.

RESULTS

The cohort included 192 conversions from LAGB to RYGB and 283 LAGB to LSG. The baseline age and BMI were similar in the 2 groups. Statistical comparisons made between the 2 groups at 24 months postconversion were significant for BMI (RYGB = 32.93, LSG = 38.34, P = .0004), percent excess BMI lost (RYGB = 57.8%, LSG = 29.3%, P < .0001), and percent weight loss (RYGB = 23.4%, LSG = 12.6%, P < .0001). However, the conversion to RYGB group had a higher rate of reoperation (7.3% versus 1.4%, P = .0022), longer operating room time (RYGB = 120.1 min versus LSG = 115.5 min, P < .0001), and longer length of stay (RYGB = 3.33 d versus LSG = 2.11 d, P < .0001) than the LAGB to LSG group. Although not significant, the conversion to RYGB group had a higher rate of readmission (7.3% versus 3.5%, P = .087).

CONCLUSION

Weight loss is significantly greater for patients undergoing LAGB conversion to RYGB than LAGB to LSG. However, those undergoing LAGB conversion to RYGB had higher rates of reoperation and readmission. Patients looking for the most effective weight loss surgery after failed LAGB should be advised to have RYGB performed, while also understanding the increased risks of the procedure.

Factor VIII elevation may contribute to portomesenteric vein thrombosis after laparoscopic sleeve gastrectomy: a multicenter review of 40 patients

BACKGROUND

Portomesenteric vein thrombosis (PMVT) has been increasingly reported after laparoscopic sleeve gastrectomy (LSG). Factor VIII (FVIII) is a plasma sialoglycoprotein that plays an essential role in hemostasis. There is increasing evidence that FVIII elevation constitutes a clinically important risk factor for venous thrombosis.

OBJECTIVES

To report the prevalence of FVIII elevation as well as other clinical characteristics in a multicenter series of patients who developed PMVT after LSG.

SETTING

University hospitals.

METHODS

A retrospective review was conducted of all patients that developed PMVT after laparoscopic bariatric surgery from 2006 to 2016 at 6 high-volume bariatric surgery centers.

RESULTS

Forty patients who developed PMVT postoperatively, all after LSG, were identified. During this timeframe, 25,569 laparoscopic bariatric surgery cases were performed, including 9749 LSG (PMVT incidence after LSG = .4%). Mean age and body mass index were 40 years (18-65) and 43.4 kg/m² (35-59.7), respectively. Abdominal pain was the most common (98%) presenting symptom. Of patients, 92% had a hematologic abnormality identified, and of these, FVIII elevation was the most common (76%). The vast majority (90%) was successfully managed with therapeutic anticoagulation alone. A smaller number of patients required small bowel resection (n = 2) and surgical thrombectomy (n = 1). There were no mortalities.

CONCLUSIONS

A high index of clinical suspicion and prompt diagnosis/treatment of PMVT usually leads to favorable outcomes. FVIII elevation was the most common (76%) hematologic abnormality identified in this patient cohort. Further studies are needed to determine the prevalence of FVIII elevation in patients seeking bariatric surgery.

Changes in Lipid Profile of Obese Patients Following Contemporary Bariatric Surgery: A Meta-Analysis

BACKGROUND

Although metabolic surgery was originally performed to treat hypercholesterolemia, the effects of contemporary bariatric surgery on serum lipids have not been systematically characterized.

METHODS

MEDLINE, EMBASE, and Cochrane databases were searched for studies with ≥ 20 obese adults undergoing bariatric surgery (Roux-en-Y gastric bypass [RYGBP], adjustable gastric banding, biliopancreatic diversion [BPD], or sleeve gastrectomy). The primary outcome was change in lipids from baseline to 1 year after surgery. The search yielded 178 studies with 25,189 subjects (preoperative body mass index 45.5 ± 4.8 kg/m(2)) and 47,779 patient-years of follow-up.

RESULTS

In patients undergoing any bariatric surgery, compared with baseline, there were significant reductions in total cholesterol (TC; -28.5mg/dL), low-density lipoprotein cholesterol (LDL-C; -22.0 mg/dL), triglycerides (-61.6 mg/dL), and a significant increase in high-density lipoprotein cholesterol (6.9 mg/dL) at 1 year (P < .00001 for all). The magnitude of this change was significantly greater than that seen in nonsurgical control patients (eg LDL-C; -22.0 mg/dL vs -4.3 mg/dL). When assessed separately, the magnitude of changes varied greatly by surgical type (Pinteraction < .00001; eg, LDL-C: BPD -42.5 mg/dL, RYGBP -24.7 mg/dL, adjustable gastric banding -8.8 mg/dL, sleeve gastrectomy -7.9 mg/dL). In the cases of adjustable gastric banding (TC and LDL-C) and sleeve gastrectomy (LDL-C), the response at 1 year following surgery was not significantly different from nonsurgical control patients.

CONCLUSIONS

Contemporary bariatric surgical techniques produce significant improvements in serum lipids, but changes vary widely, likely due to anatomic alterations unique to each procedure. These differences may be relevant in deciding the most appropriate technique for a given patient.

The utility of radiological upper gastrointestinal series and clinical indicators in detecting leaks after laparoscopic sleeve gastrectomy: a case-controlled study

BACKGROUND

Leak after laparoscopic sleeve gastrectomy (LSG) often presents after hospital discharge, making timely diagnosis difficult. This study evaluates the utility of radiological upper gastrointestinal (UGI) series and clinical indicators in detecting leak after LSG.

METHODS

A retrospective case-controlled study of 1762 patients who underwent LSG from 2006 to 2014 was performed. All patients with radiographically confirmed leaks were included. Controls consisted of patients who underwent LSG without leak, selected using a 10:1 case-match. Data included baseline patient characteristics, surgical characteristics, and UGI series results. Clinical indicators including vital signs, SIRS criteria, and pain score were compared between patients who developed leak and controls.

RESULTS

Of 1762 LSG operations, 20 (1.1 %) patients developed leaks and were compared with 200 case-matched controls. Three patients developed leak during their index admission [mean = 1.3 days, range (1, 2)], while the majority (n = 17) were discharged and developed symptoms at a mean of 17.1 days [range (4, 63)] postoperatively. Patients diagnosed with leak were similar to controls in baseline and surgical characteristics. Contrast extravasation on routine postoperative UGI identified two patients with early leaks, but was negative in the remainder (89 %). Patients with both early and delayed leaks demonstrated significant clinical abnormalities at the time of leak presentation, prior to confirmatory radiographic study. In multiple regression analysis, independent clinical factors associated with leak included fever [OR 16.6, 95 % CI (4.04, 68.10), p < 0.0001], SIRS criteria [OR 7.0, 95 % CI (1.47, 33.26), p = 0.014], and pain score ≥9 [OR 19.1, 95 % CI (1.38, 263.87), p = 0.028].

CONCLUSIONS

Contrast extravasation on routine postoperative radiological UGI series may detect early leaks after LSG, but the vast majority of leaks demonstrate normal results and present 2-3 weeks after discharge. Therefore, clinical indicators (specifically fever, SIRS criteria, and pain score) are the most useful factors to raise concern for leaks prior to confirmatory radiographic study and may be used as criteria to selectively obtain UGI studies after LSG.

Location and number of sutures placed for hiatal hernia repair during laparoscopic adjustable gastric banding: does it matter?

BACKGROUND

It has been demonstrated that hiatal hernia repair (HHR) during laparoscopic adjustable gastric banding (LAGB) decreases the rate of reoperation. However, the technical aspects (location and number of sutures) are not standardized. It is unknown whether such technical details are associated with differing rates of reoperation for band-related problems.

METHODS

A retrospective analysis was performed from a single institution, including 2,301 patients undergoing LAGB with HHR from July 1, 2007 to December 31, 2011. Independent variables were number and location of sutures. Data collected included demographics, operating room (OR) time, length of stay (LOS), follow-up time, postoperative BMI/%EWL, and rates of readmission/reoperation. Statistical analyses included ANOVA and Chi squared tests. Kaplan-Meier, log-rank, and Cox regression tests were used for follow-up data and reoperation rates, in order to account for differential length of follow-up and confounding variables.

RESULTS

There was no difference in length of follow-up among all groups. The majority of patients had one suture (range 1-6; 55 %). Patients with fewer sutures had shorter OR time (1 suture 45 min vs. 4+ sutures 56 min, p < 0.0001). LOS, 30-day readmission, band-related reoperation, and postop BMI/%EWL were not statistically significant. Anterior suture placement (vs. posterior vs. both) was most common (61 %). OR time was shorter in those with anterior suture (41 min vs. posterior 56 min vs. both 59 min, p < 0.0001). Patients with posterior suture had a longer LOS (84 % 1 day vs. anterior 74 % 1 day vs. both 74 % 1 day, p < 0.0001). There was no difference in 30-day readmission, band-related reoperation, and postoperative BMI/%EWL.

CONCLUSIONS

Patients with fewer or anterior sutures have shorter OR times. However, 30-day readmission, band-related reoperation, and postoperative weight loss were unaffected by number or location of suture. The technical aspects of HHR did not appear to be associated with readmission or reoperation, and therefore a standardized approach may not be necessary.

Evaluating gastric erosion in band management: an algorithm for stratification of risk

BACKGROUND

Laparoscopic gastric banding has several known complications, including gastric erosion. No clear factors have been determined for the development of band erosion, but technical factors such as covering the buckle of the band have been implicated. The objective of the present study was to determine whether band management after surgery, band size, or filling beyond the manufacturer-determined maximal volume has an effect on the incidence of erosion at a university hospital in the United States.

METHODS

We performed a retrospective review of a prospective institutional review board-approved database. All patients who had been followed from 2002 to 2008 were identified. The maximal band volume was 4 cm(3) for the 9.75-cm/10-cm band and 10 cm(3) for the Vanguard band. The bands were considered overfilled if they had been filled to greater than the maximal volume for >/=3 months.

RESULTS

A total of 2437 patients had undergone Lap-Band surgery. Of these 2437 patients, 14 developed erosion (.57%). The primary erosion rate was .39% (9 of 2359). These patients were divided into 3 groups according to the type of band placed: group 1, Vanguard (n = 735); group 2, 9.75-cm/10-cm band (n = 1624); and group 3, revisions to Vanguard, including a band placed around a bypass (n = 78). The incidence of gastric erosion by group was .95% (7 of 735) in group 1, .12% (2 of 1624) in group 2, and 6.41% (5 of 78) in group 3. The difference in the erosion rate among the groups was significant (group 1 versus 2, P = .005; group 3 versus 1, P = .003; and group 3 versus 2, P = .001). Erosions developed in each group without overfilling. Also, comparing the erosion rate in the overfilled versus underfilled bands, statistical significance was found only for group 1 at 3.18% versus .35% (P = .006). The erosion rate in the overfilled versus underfilled was 1.01% versus .07% in group 2 and 11.11% versus 3.92% in group 3.

CONCLUSION

A band that needs to be overfilled might be a sign of erosion, and patients should undergo endoscopy. Band revision has a greater rate of erosion than primary banding. The Vanguard band has a greater risk of erosion than the 4-cm(3) bands.